Before Forever Ends
by Flyte4
Summary: No one ever knew. Never knew what the Tesseracts was. Never knew of its power. Never knew it was sentient. No one knew it was sentient, save for those it had inhabited. Credit for the cover image goes to Sheridan-J on Deviantart. Comments welcome. This is not a romance story. Yes, their is a relationship between two women, but that is not the focal point.
1. Touch

Toasters. Erin hated toasters. They were simple enough, really. Put the bread in the slot. Push the button. Wait a few minutes, and enjoy crispy hot bread. But for her? They never worked. For her, the sequence was a little different. Put the bread in the slot. Push the button. Wait a few seconds, and enjoy the impromptu mini fireworks display, then begin browsing where to buy a replacement toaster. Or, if she was lucky, all she had to do was throw away the mangled, burnt remnants of what might had been bread. Or, if she was luckier, nothing at all would happen.

Logically thinking, Erin always managed to be the person for whom a defect burned spectacularly. She was the statistical one to a million. But of course, her own theory was slightly different. Erin firmly believed that toasters were conspiring against her. Somehow. She wasn't exactly sure how, really, but oh, yes. They were. Mocking her every time she wanted toast.

The only time Erin could really have toast was when her girlfriend was home. Which, regrettably, wasn't often. Natasha was a busy woman. To be fair, so was Erin, but while her work with a diagnostic lab in Queens was fairly steady, Nat's jobs took her all over the world at the drop of a hat. It was stressful, really. Erin was aware of the general terms of Natasha's job, but the redhead would never discuss specifics. And Erin never pressed. The often-unexplained scabs and bruises were disturbing, but Erin trusted Natasha. If she didn't want to talk about it, she probably had a reason.

But back to toast.

"Nat!" Erin whined, picking out the black scraps of bread from the shiny, brand new (as of last Thursday) toaster. No matter how often she failed at using the simple machine, Erin was always ready to try again, doggedly believing that someday, she would succeed. "I need your help."

"Just pour some cereal," Natasha sighed in response, her spoon clinking softly against the clear glass bowl of, of course, cereal as she ate her own breakfast, perched on the edge of the sleek granite countertop, glancing at the morning news program muted on the television screen. "Stop torturing the toaster."

But of course, that would be admitting defeat.

"No look," the brunette pressed, pulling two new slices of bread from the clear plastic bag. "I'll put it in. You just need to press the lever. It always works when you do it."

Liquid green eyes glanced up at her, one graceful brow arching in exasperation. They had this same conversation every morning Natasha was home. She couldn't understand why Erin didn't just have cereal. It was so much simpler. But Natasha wouldn't complain. These conversations felt so... domestic. The sensation was oddly welcome, when the rest of her life was the exact opposite of domestic. Case and point, displayed on the news: the Triskellion burning in Washington. Two weeks ago, actually. The events leading up to the climactic exposure of SHIELD had been confusing, terrifying, even. Natasha's eyes drifted to her pajama-clad lover, brooding silently. Erin was a constant in her chaotic life. She kept Natasha sane.

The Russian brought the bowl to her lips and drank the milk, sweetened by the cereal, before setting it down to the side. She slipped off the countertop, landing easily on her feet, and drew closer to her lover. Natasha wrapped her arms around the blonde's waist, pressing her lips to the pale curve of Erin's shoulder, her cheek brushing against the spaghetti strap of Erin's tank top.

"What time do you need to be at work, today?" she murmured, tipping her chin up to rest it against the crook of Erin's neck.

Erin settled easily back into Natasha's hold, smiling. The redhead wasn't shy about carrying out any ideas that popped into her head. Not that Erin minded. She enjoyed physical contact.

"Nine," she replied, dropping one hand to curl her fingers around the slightly-shorter woman's hands. "Same as every day."

"So we have time."

Erin found herself with her back to the counter, chest to chest with Natasha. The other woman's hand caressed Erin's smooth thigh, gliding down to cup under her knee, to pull it up to Natasha's own hip. The brunette rolled her eyes in mock exasperation.

"Seriously, Nat? I already took a shower. Can't get dirty again." The soft, halfhearted protests were nullified by the way Erin responded, draping one arm loosely around Natasha's neck, tipping up her face to brush her own soft lips to those of her girlfriend. Natasha gave the blonde a knowing smirk, more than willing to intensify the gentle half-kiss.

But duty called. Natasha's cell phone lit up to the left, buzzing insistently. A capital A hovered a few inches above the phone's screen, courtesy of Tony's upgrades. Natasha's eyes flitted over to the screen, before meeting Erin's eyes with an apologetic look. The other woman sighed, offering a halfhearted smile in return.

"I know; I know. Duty calls."

Erin slid down, diving Natasha a gentle nudge towards the bedroom to change from the, well, very little she wore to sleep, into one of the catsuits that seemed to be her uniforms. Natasha darted out of sight, silently gearing up with a swiftness born of practice. The brunette frowned softly, eyes drifting over to the television where the news station was now depicting the weather for the day. Storms were predicted. Awesome. She found herself a mug and microwaved water for tea. Coffee was good, especially in the morning, but Erin needed to relax. Her heart rate skyrocketed in a way that wasn't good whenever Natasha was given the call to 'assemble'. There was never a guarantee that things would turn out alright.

So Erin made her tea. It wasn't exactly her favorite drink, but it did help to soothe her. She gave the toaster a longing glance after setting a mug of water into the microwave, before giving in a pulling a cereal bowl from the cabinet. She would retrieve the untoasted bread from the toaster in a moment.

She hated cereal. It always tasted stale, to her. Overly sweet. And she wasn't a fan of milk. Natasha knew that. Erin knew, too, that she was being immature about the whole subject of milk and cereal, but she just couldn't bring herself to enjoy it. The plastic bag inside the cereal box rustled softly as she opened it, but a firm hand on hers distracted Erin from her task.

"I'll come back," Natasha promised, pressing her lips to Erin's cheek as she reached around, and pressed the button on the toaster. The other woman dipped her head in acknowledgement, a small smile lifting the the corners of her lips.

"I know. You always do."

Erin left the apartment an hour later, in casual clothing acceptable for the lab. No open-toed shoes, no pants that ended above the calf, and no long sleeves. The doorman smiled and wished her a nice day as she strode out, and Erin tossed a similar greeting over her shoulder before setting to work with hailing a cab. Within the hour, Erin was at the diagnostics lab in Queens, washing her hands and snapping on the lavender nitrile gloves to begin her work.

Nine to six, was her work day. Sometimes it was interesting. Sometimes it was bland. Sometimes it was simply depressing. At least two out of every five cultures sent her way for identification were drug resistant of some kind. It was frustrating, to be honest. She was able to identify them easily, but damn, she was sure some of the people from whom the cultures had been collected were on medication that was ineffective. In some cases, it was merely a nuisance, to change medication after a few days. For others? Maybe it was a matter of life and death.

Noon rolled around, and she paused for lunch in the break room. Then six o'clock showed up, and she hung up her lab coat and headed back out the door.

Typically Erin would hang around in a nearby cafe until the tail end of rush hour traffic died down. Today was no different. From the cafe, she would take the cab again, back to her home. The doorman would greet her on the way in, as he always did. The receptionist wouldn't even glance up. The elevator took forever, as usual, and when Erin walked in the door, she kicked off her shoes and wandered into the kitchen space in her socks, eager to put on a pot of coffee. As the drink percolated through the coffee machine, Erin drifted into the bedroom she shared with Natasha, to grab the book the had been reading the night before, before falling asleep. The thin, pale curtains were still drawn against the sunlight from that morning, so Erin passed by the windows and flicked them opening, reveling in the East River view for a moment, before snatching her well-worn paperback from the bedside table. She thumbed through the pages idly as she padded back into the main space, unbothered by the silence of the apartment, which was only broken by the gentle burbling of the coffee maker.

What did bother her, though, was the shimmering blue light that blinder her without warning.

It shimmered and danced like a cool blue flame, filling her vision as though she were looking straight into the sun. The deep whoosh of a sudden burst of flame on a film of pure alcohol accompanied the strange light, conflictingly gentle compared to the raw intensity of the light.

"Jesus Christ!" she spat, jerking back from the light reflexively the moment it appeared. She collided with a lamp table, sending the bud vase adorning it topping to the floor to shatter gracelessly as she dropped her book, covering her smarting eyes.

The scent of something burning caught Erin's attention within a few moments, and she forced her hands down, blinking to clear the spots from her vision as she sought out the source of the smoke.

It was easy to find, actually. Smoke curled up in a sensuous dance from a perfectly round circle of soot in the hardwood flooring. A cube, shimmering with the colors of an autumn sky, rested perfectly unharmed within the circle. Erin wasn't entirely certain what she was looking at. That the apparition of a blue box in her living room was abnormal, she was certain. She stared blankly, for a moment, trying and failing to comprehend, before stepping cautiously closer.

It didn't matter, that she was currently doing exactly what she had criticized countless SciFi characters for doing. It didn't matter, that logic dictated she call someone who might know what the hell the cube was. At the moment, as she neared the blue box, Erin only had an inexplicable, overwhelming desire to touch it.


	2. Options

Night had well and truly come, by the time Natasha returned home. The daylight crowd had gone home hours ago, and the city had smoothly transitioned over to the hands of the nocturnal. The steady thrum of traffic dulled behind her as the lobby's soundproofed doors slid shut behind her, and Natasha sighed, flicking a strand of sweat-caked red hair from her face. She touched her lip gingerly, feeling over the split skin. Erin was going to worry about that.

The call hadn't been that serious, actually. Doom had shown up with the intention of exacting revenge upon, well,whoever he was upset with this time. The masked man had released a hoard of little gremlin-like robots in Time Square, booming out that 'all shall fear my deadly robotic army!' Deadly? Mmm, not so much. Something must have shorted out in their programing if they were intended to be deadly. Annoying? Yes, very. The cat-sized gremlin bots had scampered around acting like a hoard of poorly behaved frat brothers, fighting each other, breaking things, harassing people in general, with a strange fixation on alcohol. One of them had thrown a full can of beer lifted from a tourist at Natasha while she was busy frying the circuits of another. Hence the split lip.

Doom had been subdued easily enough. The kill code for his 'deadly robotic army' had been acquired, and then all that was left was a cleanup of the immobile gremlins. Erin would likely have seen it on the news. Doom was usually the Fantastic Four's problem, but this time, the Avengers had been closest.

Natasha slipped her key in the lock and opened the door, trying to be as quiet as possible. Erin was probably asleep, and she wasn't exactly a pleasant person when she was tired. But something was off. All the lights were still on. The brunette was meticulous about shutting off every light in the apartment before she went to sleep, so she probably wasn't in bed yet, but then again, she rarely stayed up past midnight.

"Erin?" Natasha ventured, padding in cautiously. She moved silently, the subtle paranoia that had kept her alive plucking at the back of her mind. The faint scent of wood smoke touched her awareness.

The apartment was bright and open, so the moment Natasha cleared the relatively closed-off entryway, she found Erin. The woman was crumpled in a graceless heap beside the remnants of a ceramic lamp. Every muscle in her body seemed to have tensed up, but she didn't move. Not even a twitch.

"Hey, Erin," Natasha tried again, spanning the room in an instant, before dropping to her knees beside the immobile woman. The spy rolled her partner over and checked her pulse, carefully searching the brunette's strained face. Erin's eyes were half lidded, locked on a distant, unseen point. The warm, deep brown of her irises was marred, webbed by a pattern of intense, icy blue that shifted and shimmered like the lacework of sunlight on the bottom of a clear pool. The sight raised the hairs on the back of Natasha's neck. Clint. Clint's eyes had looked like a duller, frozen version of that, when he had attempted to kill her on Loki's orders.

Loki. Was it Loki who had done this? Damnit, she thought Thor had said he was dead. Natasha drew Erin up protectively against herself, her eyes, dark with anger, skimming around the room. The brief search revealed nothing, though, save a washed-out blue box. Damn. This was just getting better and better.

In all honesty, the box looked like the Tesseract. Same size, same shape, same color, more or less. The light it had emitted was gone, though, like all of its infinite energy had been sucked away. But Natasha's first priority was her partner.

Natasha maneuvered Erin onto the flat, white sofa. She pulled the plush blanket Erin usually kept there for chilly evening from the back of the sofa and draped it over the woman, tucking the edges under the other's body to provide a warm pocket of comfort. The next priority was to call Stark. The egotistical inventor wasn't exactly her favorite person, but she trusted him with her life, and now, that of her partner. Predictably, Natasha was met with the posh voice of Stark's British AI butler.

"Good evening, Ms. Romanov," JARVIS promptly answered before the phone even had time to ring. "Sir is currently unavailable. He has asked me to apo-"

"JARVIS, I don't care what he's doing with Pepper right now," she broke in, her voice smooth and level. "This is an emergency, okay? Tell him I've got a little blue cube in my apartment, and tell him to bring his suit."

There was a pause, and then: "Sir will be leaving momentarily, Ms. Romanov."

"Great. Have him meet me on the roof."

Natasha dropped her phone, running a hand over her face. What was going on? She allowed herself to sit there blankly for a few moments, before standing up again. The Tesseract was draped with a kitchen towel, then shoved into a gaudy Christmas-themed handbag Thor had once given her in his first attempt to participate in Christmas gift-giving. Natasha set it on the floor by the sofa and retrieved a quilt, shoving that in the bag as well. She glanced at Erin, who hadn't moved a muscle, and slung the bag over her shoulder.

The room was silent, still, as Natasha hoisted Erin up from the couch. She managed to half support, half drag Erin from the apartment, and down the hall to the elevator. Once the car reached the last floor it would hit, Natasha slipped out of the elevator and hauled Erin up the maintenance stairs, to the roof, where she gingerly set Erin to the ground. Even on a clear summer night, the New York air had a slight chill to it, from the air blowing in off of the water. Natasha dropped the quilt over Erin.

It had been four years as of April, that Natasha and Erin had been together. It had begun as a few random encounters in a coffee shop they both seemed to enjoy. Erin had made the first real move, asking Natasha to accompany her to one of the many history museums. Things had more or less snowballed from there. Natasha hadn't ever intended to find a partner to stick with. Love was for children, and she didn't consider herself to be the marrying type, and even more importantly, anyone she grew close to was in danger. Living with Erin in a civilian setting likely hadn't done anything to lessen that danger, but Natasha had done what she could, to keep Erin safe. Their neighbors were SHIELD agents, or, they had been, and the new post-doc working with Erin in Queens was an old acquaintance who owed Natasha a big favor. Erin, upon Natasha's insistence, had taken self defense courses and carried a taser with her everywhere. But even so, not everything could be guarded against. Case and point was wrapped in a dish towel in a gag-gift handbag.

Stark flashed through the air like an egotistical comet, not much later, and landed with a dull clank on the rooftop. His faceplate flicked up, revealing a very unamused expression beneath.

"This better be good," he grumbled, looking decidedly like a grumpy child.

Natasha didn't particularly care. She gestured to Erin. "I need you to take her back to your building." Out of reflexive habit, she scanned the rooftop, before lowering her voice. "When I came home, Erin was on the floor and the Tesseract was burning the floor. I need her in a safe place. No more questions. Go."

"Okay fine. I guess this counts as good," Stark grumbled, kneeling down to gather up Erin's still form. It was fortunate that Natasha had brought a quilt. The flight over would be cold, and he bet his best case of scotch the assassin would kick his ass if Erin ended up with windburn on top of whatever freaky shit was going on. Natasha shoved the Christmas bag into his arms as well.

"I'll be there in ten minutes."

No, she didn't particularly care that the drive was twenty minutes on a good day. She would make it in ten.

When Tony Stark touched down on his landing pad, Pepper was waiting for him, regrettably redressed. Her arms were folded, curiosity and a bit of confusion plain on her expressive face.

"Who's this?"

"Um..." He weighed the options. Tell Pepper and have Natasha bite his head off about it later? Or have Pepper bite his head off for lying to her? He chose the lesser of two evils. "Tasha's girlfriend."

The reaction he received was, understandably, surprise. Natasha kept her personal life secret. Tony had only learned of Erin by accident, when he stole Natasha's phone in an attempt to change all of her contacts to 'Batman'. Damn, did she have heavy security on that phone. It had taken Jarvis an hour to crack her three different passwords. Understandably, Natasha had exacted her revenge for Tony's breach of her privacy, and sworn him to secrecy with a very colorful threat.

But Pepper could be scarier.

"What happened?"

"That's kinda what we're trying to find out, Pep. Jarvis. I want every scanner in the lab up and running by the time I get down there."

There was a brief pause as he settled Erin on the couch and let his armor fold away, before it dawned on him that maybe it would have been easier to carry Erin if he had left the suit on.

"Help me get her downstairs, please oh please oh beautiful CEO of mine?"

Pepper roles her eyes and approached the couch, helping Tony lift Erin from the sofa. The Christmas bag was snatched up as well, and after a bit of tricky maneuvering, Tony and Pepper had Erin laid back on a hastily-cleared table away from most of the important things in Tony's lab. Not that not everything was important. Away from most of the most important things. Dummy and You were slowly gliding fancy-looking scanners a few inches away from Erin's body, and Tony was dubiously hooking Butterfingers up with a third. Various monitors held the readouts. Elevated body temp. Elevated heart rate. Elevated brain activity. The energy readings she was shooting out were nothing to sneeze at either. Obviously, they were identical to those of the Tesseract. Low levels of Gamma radiation, bioenergy fields, nothing too harmful. He was a little worried about the Gamma, though. Natasha would kill him if Erin turned big and green, but hey, Bruce would have a 'hulk smash' buddy.

More in depth scanning revealed a mass of raw, pulsating energy shimmering out of sight, coursing through her body via nervous system, but remaining largely centered around her brain. Tony grimaced. This better not be mind control. He hated mind control.

When Natasha arrived roughly six minutes later, having broken every traffic law the city had, Tony was checking Erin's odd mottled eyes. The Tesseract, which now sported a fine hairline fracture angling from one corner to another, was safely locked away in a small-scale containment model Tony had built to test whether his machine to dampen Asgardian magic worked. It had, and to test it on a larger scale, he had installed a bigger version of the dampener in the tower and tested it on Thor. Thor had been unnerved by having his powers stripped away again, despite having agreed to the test. Tony had felt sorry for the big man, and kept it off.

"You... do realize I'm not a doctor, right? I have no idea what I'm doing."

"Comforting, Stark," was the terse reply. Pepper was off to the side seated by a desk, dozing tiredly on the cluttered surface. She wasn't as well-adapted to survive without sleep as Natasha and Tony.

"I try. Here's what I got. She has a fever, nothing serious, and her heart rate's a bit high. Stress, I'm guessing." He gestured with his hand and the scans of her nervous system popped up, flaring to life with bright blue. "This isn't exactly normal, in my expert opinion. Her energy signals are lighting up like the fourth of July. Kinda surprising that the little pulses aren't hurting anything. I mean, out here. She's fine, as far as I can tell." Natasha's eyes had darkened in a way that meant trouble.

"I'm gonna take a blood sample. Don't shoot me."

Natasha tensed at the sight of the needle, then relaxes. Erin hated needles, but she was out cold. She wouldn't need to be held down as she usually did. If Natasha hadn't known Tony for the years she had, she would have been more than a little suspicious of the fact that Tony kept a box of needles in his lab. But she had known Tony, and she had learned early on that the billionaire avoided hospitals and doctors' offices like the plague, and did most of his own diagnostics, no matter how inadvisable the decision was.

"I'm not going to shoot you." Natasha folded her arms and watched closely as Tony pressed the freshly-unwrapped sterile needle to the crook of Erin's elbow.

And instinctively ducked and drew her weapons a split second later as bright blue exploded out from the table, accompanied by a fierce thrum. The needle fell to pieces in Tony's hand, literally crumbling while he himself remained shocked, but unharmed.

"Uh, scratch what I said earlier. The energy's kinda dangerous."

What had that been about? Did touch trigger it? Natasha had been tugging on Erin earlier, trying to move her up to the roof. Both he and Pep had manhandled Erin into the lab. Maybe touch wasn't the factor. The needle? Did the needle set it off?

"Don't do that again," Erin murmured, her eyes still closed. An immense feeling of relief engulfed the stoic assassin, but something was still off. That wasn't Erin's voice. It was wrong.

This voice was lilting, mellow, and practically musical, compared to Erin's soft, soothing, earthy Brooklyn tones. It certainly wasn't Erin's voice.

Her eyes slid open. The mottling was gone, replaced by a pure, steady blue. Totally different from the warm, chocolatey brown Natasha had come to enjoy. The false Erin on the table eased herself into sitting up and tilted her head from one side to the other, a satisfying pop snapping in her ears. And then she stood. The movement was graceful, like a sensuous dancer beginning her act.

"Let's see here. Female, as I guessed. I suppose that makes things much simpler, doesn't it. Healthy, I believe. Brown hair, a nice change. Quite pleasing overall, really." The false Erin murmured to herself, looking herself over as well as she could, before snapping her eyes up to join Tony like a prize butterfly.

"The needles must remain way. My host does not like them. They bring her much fear." Erin flexed her hands, testing her control over the form.

"And being replaced by whatever you are isn't frightening?" Natasha murmured dryly, a gun aimed with deadly precision at her lover. She wouldn't shoot, couldn't, but perhaps a bluff would work. "I'm going to need you to leave."

Erin tilted her head, a small smile appearing on her face. "I'm afraid I have no intention of doing so. At the moment, this is the safest place." She inspected her- Erin's nails and, seeming satisfied, took the time to glance around the room. Her eyes didn't linger for the barest moment on the handgun trained her way.

"You are aware that the safety is on, are you not? You don't particularly seem like the type to forget such a thing, which leads me to believe you will not risk firing. Mr. Stark, I would advise against that."

Tony's finger hovered above the subtle switch embedded in his lovely control panel of master switches. The one to the magic-dampener.

"Yeah, um, why? Why exactly shouldn't I press this button?" The false Erin smiled.

"Allow me to walk you through the options. You press that button, which, I believe, is an attempt to restrict me. I overpower your system, which in turn burns down your... room. You panic and attempt to separate or quarantine my host and myself, which leaves us both damaged and open to attack. Or, we sit calmly and speak over tea. I like the latter option, do you not?"


End file.
